  findABCD - discrete-time system subspace identification
  findAC - discrete-time system subspace identification
  findBD - initial state and system matrices B and D of a discrete-time system
  findBDK - Kalman gain and B D system matrices of a discrete-time system
  findR - Preprocessor for estimating the matrices of a linear time-invariant dynamical system
  findx0BD - Estimates state and B and D matrices of a discrete-time linear system
  inistate - Estimates the initial state of a discrete-time system
  sident - discrete-time state-space realization and Kalman gain
  sorder - computing the order of a discrete-time system